Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method for establishing a group cell for a cooperative transmission and a handover in a wireless communication system.
Related Art
Since a user equipment (UE) which is a representative mobile device moves, quality of a currently provided service may deteriorate or a cell capable of providing a better service may be detected. Accordingly, the UE may move to a new cell, which is called performing a movement of the UE.
A micro cell, a femto cell, and a pico cell, etc., having a small service coverage may be installed in a specific location within a coverage of a macro cell having a wide coverage. Such a cell may be called a small cell.
A heterogeneous network (HetNet) is a network in which several types of cells overlapping in the same region are simultaneously operated. Recently, since a required data amount of the UE is growing, it becomes difficult to satisfy the required data amount when using only one conventional macro cell. Therefore, a HetNet topology and a small cell concentration architecture are proposed to increase overall network capacity and to improve energy efficiency by allowing a small-scale region to be served using a low-power micro cell, femto cell, pico cell, or the like. A research is underway for this as one of study items of the 3GPP LTE standard. With the ongoing miniaturization and concentration of the cells, there is a growing interest on an inter-cell cooperative transmission technique and a technique for processing a frequent handover of a mobile user.